Datatype/Physical Database/Logical Database/Schema Object Naming/Process / Runtime/ Limits ......

Oracle 8.0.x and 8.1.x Database Limits

Datatype Limits

Datatypes

Limit

Comments

BFILE

maximum size: 4GB

maximum size of file name: 255 characters

maximum size of open BFILEs: see comments

The maximum number of BFILEs is limited by SESSION_MAX_OPEN_FILES, which is itself limited by the maximum number of open

files the operating system will allow.

BLOB

4GB maximum

The number of LOB columns per table is limited only by the maximum number of columns per table (i.e., 1000)

CHAR

2000 bytes maximum

CHAR VARYING

4000 bytes

CLOB

4GB maximum

The number of LOB columns per table is limited only by the maximum number of columns per table (i.e., 1000)

Literals (characters or numbers in SQL or PL/SQL

4000 characters maximum

LONG

2³¹-1 bytes (2GB) maximum

Only one LONG column allowed per table

NCHAR

2000 bytes

NCHAR VARYING

4000 bytes

NCLOB

4GB maximum

The number of LOB columns per table is limited only by the maximum number of columns per table (i.e., 1000)

NUMBER

999...(38 9's)x10 to power of 25

maximum value

-999...(38 9's)x 10 to power of 125 minimum value

Can be represented to full 38-digit precision (the mantissa).

Precision

38 significant digits

RAW

2000 bytes maximum

VARCHAR

4000 bytes maximum

VARCHAR2

4000 bytes maximum

Physical Database Limits

Item

Type of Limit

Limit Value

Database Block Size

minimum

maximum

2048 bytes; must be a multiple of O/S physical block size

O/S-dependent never more than 32KB

Database Blocks

minimum in initial extent of a segment

maximum per datafile

2 blocks

platform dependent; typically 2 to power of 22 blocks

Controlfiles

number of controlfiles

1 minimum: 2 or more (on separate devices) strongly recommended

size of controlfile

dependent on O/S and database creation options; maximum of 20,000 x (database block size)

Database files

maximum per tablespace

maximum per database

O/S dependent, usually 1022

65533; may be less on some operating

systems; limited also by size of database blocks, and by the DB_FILES init parameter for a particular instance

Database file size

maximum

O/S dependent, limited by maximum O/S file size; typically 2 to power of 22 or 4M blocks

MAXEXTENTS

default value

maximum

derived from tablespace default storage or DB_BLOCK_SIZE

unlimited

Redo Log Files

maximum number of logfiles

maximum number of logfiles per group

LOG_FILES initialization parameter, or

MAXLOGFILES in CREATE DATABASE; controlfile can be resized to allow more entries; ultimately an O/S limit

Unlimited

Redo Log File Size

minimum size

maximum size

来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/45259/viewspace-134947/ ，如需转载，请注明出处，否则将追究法律责任。

上一篇： Convert long to char

下一篇： An example of ref cursor(1)

请登录后发表评论登录

全部评论

dragondb

注册时间：2003-05-05

博文量
98
访问量

94093

ITPub博客

Database limits(8i/9i)

最新文章